Patent Literature 1 relates to an authentication method in which, upon user registration, an authenticating apparatus transmits an address for a registration screen to a communicating apparatus of a user. The address for a registration screen includes a registration identifier that identifies the user and/or the communicating apparatus. When the communicating apparatus transmits a first password that is input to the registration screen to the authenticating apparatus, the authenticating apparatus authenticates a user based on the registration identifier and the first password. When the authentication is successful, the authenticating apparatus transmits a login screen to the communicating apparatus. The login screen includes a login identifier that identifies the user and/or the communicating apparatus. The communicating apparatus transmits a second password that is input to the login screen to the authenticating apparatus. The authenticating apparatus authenticates the user based on the login identifier and the second password.
However, Patent Literature 1 conceivably requires further improvements.